This invention concerns wrapping of pasty or moldable food products such as butter or margarine. Butter and margarine are commonly molded into quarter pound or one pound pieces in the form of elongated blocks referred to as sticks. The product sticks are then individually wrapped in grease impervious printed sheets prior to being packaged four to a package in paper cartons.
Wrapping of the individual product sticks is done by automated machinery in a multistage operation.
The wrapped sticks are then conveyed to a packaging machine which may also be included in the same apparatus, where four wrapped sticks are gathered to make up a one pound package.
Heretofore, the molding and wrapping operation have been conducted in a series of separate stations in the machine with transport of the product and sheet successively through a number of individual stations. Such transport is by a large carrier disc, operated with a geneva wheel motion or with a linear conveyor. In each station, a portion of the steps required to complete the product wrapping operation is carried out.
In applicant's U.S. Pat. No. 5,794,411 issued on Aug. 18, 1998, a single station simplified food product wrapping machine is disclosed and claimed.
That machine uses a single folding frame which may have a series of rectangular through cavities, one cavity for each stick to be wrapped within the folding frame. Each cavity has associated therewith a series of cam and pusher devices which act on a sheet of wrapping paper as the wrapping paper is pushed through the cavity with the food stick to be wrapped such as to execute successive folding operations which result in a fully wrapped stick, which is pushed out of the cavity by the advance of the next wrapped stick.
The first camming device comprises a pair of flat rectangular blades projecting towards the cavity from each end with a clearance gap on either side of the flat blades between the sidewall of the top the folding frame. As the sheet is pushed into the cavity, the central portion of either end of the sheet is bent upwardly towards the stick end and a pair of fold wings are simultaneously formed which pass through respective gaps allowing the food stick and sheet to advance into the cavity.
A pair of chisel pointed folding cams are located on either side of the cavity, the folding cams projecting horizontally and forwardly spaced apart. The respective fold wings successively encounter the spaced cam fingers which fold the wing folds in overlapping fashion against each end of the food stick as the food stick is advanced to the bottom of the folding frame cavity.
A pair of rectangular folding blades is then advanced through slots so as to enter the cavity at a level aligned with the top of the food stick engaging the folded sheets so as to again force the sheet central regions onto the top of the folding stick, each forming opposite top wing folds which project upwardly into the cavity against upwardly projecting flaps on either side of the sheet.
A pair of top flap folding plates are recessed into the sidewall of the cavity at a level even with the top of the food stick when the food stick has been fully advanced to the bottom of the cavity. Each of the folding plates are successively pivoted into the cavity folding each top flap atop the food stick.
The next successive food stick forces the completely folded food stick out of the cavity and onto a conveyor.
While this arrangement has simplified the wrapping process, another drawback of prior wrapping machines, particularly for butter and margarine is that only one or two sticks are wrapped at a time. Four sticks are required for the typical one pound package. Thus, by wrapping only one or two sticks at a time, it takes longer to make up a one pound package, and four wrapped sticks must be processed to complete a one pound package.
It is the object of the present invention to provide a wrapping machine in which four wrapped quarter pound sticks are produced simultaneously to allow a one pound package to be made up more rapidly than with prior art machines.